dready zim:Just added 10T of intakes (4 ram intakes per turbojet now, 16 turbojets) so I was able to reduce my orbital insertion stage leaving me with a 62T craft with a TWR on jets of 5.86...

Now it gets me to 40K and 2000m/s so I might reduce my orbital insertion stage again as I still have most of my fuel left in that stage in LKO.

Can you post a screen shot of your design? I'm playing with vertical SSTO right now, and using jets for the first time. I've got just enough dv to get into a 100km orbit, but not much else. I don't think I can even re-enter without topping off at my space station.

MindStalker:LasersHurt: 45cal: Wouldn't the fuel needed to land like this from a trip into low earth orbit basically negate any payload carrying capacity?

Yes and no. The whole point of developing this is that it's far more efficient - it's a refuelable, reusable system that is far less expensive. Like, the fuel is .3 percent of the total cost of a Falcon 9. Even with the small payload hit (which they somewhat compensated for slightly with larger tanks), it's still so much cheaper that you could do dozens launches and get way more into space for your money.

Also if in the long run you can setup a refueling system in space, you wouldn't need to waste payload on double fuel. (though that would require getting fuel from space to be efficient), I think in the long run its more about things like round trip missions to Mars where building a new rocket there is pretty much impossible, but setting up a refinery system while difficult wouldn't be as hard as building a new rocket there.

Since the payload is detached and a lot of the fuel is burnt, and you're descending instead of ascending, it requires way less to come down than it did going up.

Here's my jet-powered SSTO ship. It's purpose is to ferry crew to/from orbiting ships. I just added the gear for powered landing. So far that's not gone well. I managed to get it down on the gear during the last mission, but 10 m/s was too much for the structure.

Fish in a Barrel:[i29.photobucket.com image 687x800]Here's my jet-powered SSTO ship. It's purpose is to ferry crew to/from orbiting ships. I just added the gear for powered landing. So far that's not gone well. I managed to get it down on the gear during the last mission, but 10 m/s was too much for the structure.

That seems kind of overengineered, with the struts connecting the external LRBs to the main fuselage; are those really necessary?

Kurohone:Fish in a Barrel: [i29.photobucket.com image 687x800]Here's my jet-powered SSTO ship. It's purpose is to ferry crew to/from orbiting ships. I just added the gear for powered landing. So far that's not gone well. I managed to get it down on the gear during the last mission, but 10 m/s was too much for the structure.

That seems kind of overengineered, with the struts connecting the external LRBs to the main fuselage; are those really necessary?

But thanks for showing the pic; now I get how jets are supposed to be put together. I haven't played at all with those yet.

The struts served a purpose at one point, but they're largely vestigial now. They do help me squeeze in a few more intakes. The more intakes you have, the higher you can go before the engines flame out.

The octagonal unit is a small lander can. It's there because this is a crew ferry; I need somewhere for the passenger to ride.

I'm trying to find a way to bring my space station out to Moho. I have to attach an engine to the big docking port on the bottom. First, though, I need to get a super size fuel tank and a tri-coupler full of nuclear engines into orbit and docked.. I think I have an efficiency problem. I tend not to measure things. I don't know how much my station weighs and I never calculate delta v. I just kinda eyeball and add more boosters and space tape where needed.

It's just not a space thread without Quantum Apostrophe being a dick to everyone he can for no reason.

Omeg: He believes he's the lone voice of reason, a wolf pack of one.

QA makes a valid point: i.e., space tech is the cute puppy of engineering. There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

Guided parachutes and specially cushioned landing pads for retrieving spent rocket stages make a lot more engineering sense in terms of payload impacts, but it's undeniably cool to watch a rocket back down onto the pad.

The Shuttle was undeniably cool, but it was idiotic to stick with it after it was abundantly shown that it was NOT a cheap way to space. But there was far too much an emotional attachment to it, because it was an awesome thing to watch. I consider it a minor miracle we only lost ONE on reentry. A friend of mine rode the shuttle, and I held my breath the entire time. It was one scary beast. I'd rather ride a Soyuz.

eventhelosers:not sure what that is but it brings back memories of Jupiter lander on the commodore

Wow, I have to tell a Commodore gamer to get off my lawn today. His picture was the original Lunar Lander arcade game which inspired later knock-offs like your Jupiter Lander, and which consumed many of my hard-earned childhood quarters.

mark12A:There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too. - John F. Kennedy

I'd like to point out that Grasshopper is not aeronautically stable (where air flow pressure on fins helps it go straight) which would make no difference in hovering situations. Instead thrust control is used to maintain attitude.

In addition such a booster can't be controlled as if it were a solid rigid body. It is more like a tube of jelly in a thin plastic sleeve and can flex and slosh a bit. Kudos to the algorithms in its flight control computer. It seemed when it was hovering that it wasn't straight up and down (maybe due to wind) but I didn't see any oscillations. But then again this just good control in its normal flight envelope and it may be prone to shaking itself to death slightly outside of it.

mark12A:It's just not a space thread without Quantum Apostrophe being a dick to everyone he can for no reason.

Omeg: He believes he's the lone voice of reason, a wolf pack of one.

QA makes a valid point: i.e., space tech is the cute puppy of engineering. There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

The real value of space travel is what you learn while trying to do it. Eventually more practical benefits will be possible...low gravity manufacturing, asteroid mining. But before then you need to develop the technology to do it.

Guided parachutes and specially cushioned landing pads for retrieving spent rocket stages make a lot more engineering sense in terms of payload impacts, but it's undeniably cool to watch a rocket back down onto the pad.

Parachutes don't work well at the speeds upper stages have nor can they be steered with enough precision. The 'cushioned landing pad' is the ocean when you're using parachutes. You need helicopters, ships, dive teams...

The Shuttle was undeniably cool, but it was idiotic to stick with it after it was abundantly shown that it was NOT a cheap way to space. But there was far too much an emotional attachment to it, because it was an awesome thing to watch. I consider it a minor miracle we only lost ONE on reentry. A friend of mine rode the shuttle, and I held my breath the entire time. It was one scary beast. I'd rather ride a Soyuz.

The Pyramids were hugely expensive graves but they inspired centuries of architects and engineers. I'd say they were worth it.

mark12A:It's just not a space thread without Quantum Apostrophe being a dick to everyone he can for no reason.

Omeg: He believes he's the lone voice of reason, a wolf pack of one.

QA makes a valid point: i.e., space tech is the cute puppy of engineering. There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

Guided parachutes and specially cushioned landing pads for retrieving spent rocket stages make a lot more engineering sense in terms of payload impacts, but it's undeniably cool to watch a rocket back down onto the pad.

The Shuttle was undeniably cool, but it was idiotic to stick with it after it was abundantly shown that it was NOT a cheap way to space. But there was far too much an emotional attachment to it, because it was an awesome thing to watch. I consider it a minor miracle we only lost ONE on reentry. A friend of mine rode the shuttle, and I held my breath the entire time. It was one scary beast. I'd rather ride a Soyuz.

Kitten. Moon landings are the useless housecoat; but satellites are the barnyard mouse-hunter.

RangerTaylor:I feel like I am missing something with KSP. I build a rocket. It launches. Then it lands/crashes/whatever. Am I supposed to have all the pieces unlocked to start with?

The game is still in development. IIRC there are plans to add a story mode later where you won't have access to all of the parts immediately, but for now it's just an open sandbox for you to explore. The bit you're missing between "it launches" and "it lands/crashes/whatever" is to visit some of the other planets or moons along the way. You should also look at some of the community add-ons which are available for the game.

LasersHurt:45cal: Wouldn't the fuel needed to land like this from a trip into low earth orbit basically negate any payload carrying capacity?

Yes and no. The whole point of developing this is that it's far more efficient - it's a refuelable, reusable system that is far less expensive. Like, the fuel is .3 percent of the total cost of a Falcon 9. Even with the small payload hit (which they somewhat compensated for slightly with larger tanks), it's still so much cheaper that you could do dozens launches and get way more into space for your money.

Yeah if it ends up working out like that then getting things into orbit wouldn't be such a big deal, financially speaking. There are other costs of course, but it's just such a huge money drain at the moment. There was also plans for a really long ramp to take off from, that wouldn't require separate rockets at all.

Like others have said -done years ago as DCX (Douglas Corporation Experiment) with (4) chamber modified RL10's. Full cyro lox/H2 rocket .

Was just to prove we could go bigger once technology/materials caught up and Single Stage To Orbit may work.

The Spac-X PR machine has repeated part of the trick decades later BUT a lox/kerosine booster can't overcome the physics involved for SSTO.Even in 95 with DCX's special lightweight Lox tank the weight/mass ratio wasn't enough.

SpaceyX site in Texas is the old Beal Areospace test site he purchased -many previous technologies are purchased or borrowed. However-unlike the others building all your own stuff so you control rates and quality is the right way to do it. Hasn't been partly done since McDonnell Douglas days during D1 and early Delta 2.

//Delta 2-the most reliable rocket on the planet. at 96 in a row with 4 more to go until our country throws it away for a Ukrainian built/tested booster marketed by Orital-USA! USA! (Thought we here needed jobs?)

//My friend Bernie in the prop goup for DCX was a great old school guy!RIP.

Monkeyfark Ridiculous:But I'm wondering mainly about the part where they decided to go with a powered return rather than using some kind of gliding or parachuting approach.

A rocket that hits the ocean can't exactly be refueled and reused. At best, it would require a very long refurbishment amounting to a rebuild- SRB segments from the shuttle had to go back to the factory, and I think it took a couple of years before they were put back in circulation. Theoretically, I think an Apollo capsule could have been refurbished with a fresh heatshield and reused, but at a cost that couldn't be justified.

But landing a rocket back on its pad like this is a huge savings in time and cost. It'll still need a thorough inspection and maintenance before being reused, but much, much cheaper and faster than fishing it out of the ocean.

The ONLY issue I have with recovery is the fact that rockets don't just go up to get to orbit, they head "downrange" as well, accelerating the cargo to orbital velocity. If they plan to recover the booster in another place, and bring them back, then all is well.

I remember seeing a similar test a few years back where the rocket went up to like 50 meters, then traveled horizontally a few hundred meters and touched down on another landing pad. Anyone else remember that, or have a link?

TheDirtyNacho:Still cool though as a proof of concept. We're a long way from orbit to vertical landing though. SpaceX is doing it with the individual rocket stages first.

A powered tailsitter landing like this only make sense if there's no atmosphere at the destination and you're opposing a lot less than 1G. It's a bloody stupid way to land a rocket on Earth or Venus. For the moon or Mars, it makes more sense, although it's still very wasteful in terms of fuel (and therefore mass). Opposing gravity with nothing but thrust is stupid if you have an alternative.

Hell, vertically launched rockets are pretty stupid to begin with. It's brute-force engineering - nothing elegant or efficient about it. The smart thing to do is use air-breathing engines and and wings (or a lifting body) to get yourself up into the stratosphere and then light off your rockets.

TheDirtyNacho:Quantum Apostrophe: TheDirtyNacho: Still cool though as a proof of concept. We're a long way from orbit to vertical landing though. SpaceX is doing it with the individual rocket stages first.

It's still absurd. Oh look, we have to cut on payload (the part that brings profit to supposedly "private" space, yes?) so we can have enough fuel to land on our ass like in 1950s sci-fi.

I don't understand. The math is not so hard. Right now, cost of payload = fuel + whole new launch vehicle + operations

Thus cost of payload goes down. They are sacrificing little payload to accomplish this. It's a cost/benefit analysis from there.

Well, that was the reasoning for the shuttle, too. Unfortunately the cost of prepping it for a new flight (plus its initial budget overruns) was so high it would have actually been less expensive to use the old rocket system.

mark12A:There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

The valid reason to do it now is that the lead time to do it when we DO need it is measured in decades.

Mars is pretty useless as a destination except for scientific curiosity - it's got too deep a gravity well to be useful as a base for going further out in the solar system, and the enviornment is almost as inhospitable as the moon or a large asteroid.

Now, a permanent moonbase is smart, because it does have a lot of mineral resources and COULD serve as a jumping-off point for the rest of the solar system. There's a lot of environmental benefit to moving some of the nastier industrial processes to the moon as well.

The main problem isn't getting there, it's getting there ECONOMICALLY. The cost to get to geosynchonous orbit is around $10,000 - $20,000 PER POUND. To make commercial spaceflight and lunar industry feasible, we need to lower that by at least an order of magnitude.

hardinparamedic:mark12A: There really is no valid reason *at present* to send people to the moon or Mars, but the awesome coolness of doing it makes normally rational sciency types go SQUEEEEE!

We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too. we're damn well not going to let the Russians beat us to it like they've done with space tech so far. And once we've done it, we'll abandon the program, since we've got no long-term goals other than that. - John F. Kennedy

clyph:I remember seeing a similar test a few years back where the rocket went up to like 50 meters, then traveled horizontally a few hundred meters and touched down on another landing pad. Anyone else remember that, or have a link?

Meh, looks like a potentially disastrous rocket launch video that is just put into reverse at a critical failure.

"Look, it went up and...uh...well...look, it's going back down now! Success!"

Wouldn't be able to land fully fueled. Too heavy. It will just enough extra fuel to land on one engine as an empty beer can.

/ Dunking it into the sea will scrap it. No way to know the thermal and mechanical stresses the engines and airframe received, so they can't be used again. Empty and sealed, it will float like a cork, and they can crane it onto a recovery vessel or at a minimum just tie a rope and tow it back to shore.

I remember seeing a similar test a few years back where the rocket went up to like 50 meters, then traveled horizontally a few hundred meters and touched down on another landing pad. Anyone else remember that, or have a link?You are referring to the DC-x:

Tyrone Slothrop:TheDirtyNacho: Quantum Apostrophe: TheDirtyNacho: Still cool though as a proof of concept. We're a long way from orbit to vertical landing though. SpaceX is doing it with the individual rocket stages first.

It's still absurd. Oh look, we have to cut on payload (the part that brings profit to supposedly "private" space, yes?) so we can have enough fuel to land on our ass like in 1950s sci-fi.

I don't understand. The math is not so hard. Right now, cost of payload = fuel + whole new launch vehicle + operations

Thus cost of payload goes down. They are sacrificing little payload to accomplish this. It's a cost/benefit analysis from there.

Well, that was the reasoning for the shuttle, too. Unfortunately the cost of prepping it for a new flight (plus its initial budget overruns) was so high it would have actually been less expensive to use the old rocket system.

The reusable shuttle was a sound idea in theory (and still is), but in order to get the money to make it fly they needed the Air Force. And so it had to suit military missions. Thus when designed it had to be able to abort once around in a polar orbit whilst carrying spy satellites the size of a bus. It was also spec'd for satellite retrieval - publicly said so satellites could be brought back for repair, but really it was to possibly steal Soviet satellites.

This made the vehicle very large and much more complicated. The commercial economics went out the window because it resulted in using external fuel tanks and booster rockets that were only slightly reusable.

TheDirtyNacho:The reusable shuttle was a sound idea in theory (and still is), but in order to get the money to make it fly they needed the Air Force.

It does make you wonder what the CIA is doing with theirs. Do we have a more extensive space surveillance or space warfare program than any country is admitting? It really wouldn't surprise me if the next cold war is space dominance (and not the ICBM kind these days)

TheDirtyNacho:The reusable shuttle was a sound idea in theory (and still is), but in order to get the money to make it fly they needed the Air Force. And so it had to suit military missions. Thus when designed it had to be able to abort once around in a polar orbit whilst carrying spy satellites the size of a bus. It was also spec'd for satellite retrieval - publicly said so satellites could be brought back for repair, but really it was to possibly steal Soviet satellites.

Also a a large number of shuttle missions were fully or partially classified. Lots of what was classified were experiments to test military technology along the lines of "how well can this optics package see through clouds".

Eventually launch technology and experiment automation got to the point where it became much cheaper to deploy satellites or run experiments without also sending up people.